Modern electrophysiology ("EP") catheters generally comprise a plurality of precisely spaced electrodes at the distal end of the catheter. Electric potential may be recorded across selected electrode pairs to evaluate the electrophysiologic function of the surrounding tissue. Similarly, electrical impulses may be delivered across selected electrodes to stimulate the surrounding tissue. Additionally, radio frequency ("RF") or other suitable energy may be directed to one or more electrodes to cause ablate malfunctioning heart tissue. RF ablation may be achieved by energizing a single electrode after advancing it to the desired location in the body. In such embodiments, the return electrode comprises an external plate that offers relatively large contact area with the patient's body. This arrangement spreads the return energy over the contact area rather than exiting at one location. Alternatively, two electrodes may be used such that the RF energy is applied between the two electrodes, obviating the need for an external plate.
The electrodes each have a connection to a lead at the proximal end of the catheter which may then be connected in turn to various electronic components to provide the desired function. Further, it is desirable to provide such EP catheters with a connection system so that each electrode may be quickly and individually switched from one functionality to another. Accordingly, an electronic interface, such as a switch box, may be used to allow each lead to be connected with the various types of electronic components, e.g. RF frequency generation, ECG mapping, cardiac pacing and the like, without physically plugging and unplugging the leads.
Prior art EP catheters suffer from certain drawbacks. Specifically, conventional designs for connecting EP catheters to mapping, pacing or ablating equipment make use of a cable with exposed connectors which, consequently, can inadvertently become electrically activated. For example, the exposed connectors may accidentally come into contact with a ground which is typically at some potential other than the patient ground, thereby creating an unwanted electrical circuit. This is of particular concern when dealing with the heart because stray electrical currents can cause fibrillation or undesirable tissue damage. Accordingly, there remains a need for connector systems which minimize the possibility of inadvertent electrical contact while still allowing easy electrical connection. This invention satisfies these and other needs.